Between 4 and 6 a.m. Wednesday, Nov. 27, the plant experienced a solid loss into its effluent discharge line due to a large amount of rainfall in a short amount of time and construction on the plant, according to a news release from the Town of Chesapeake Beach. An estimated 60,000 gallons of partially treated effluent were discharged into the bay through a discharge pipe, according to the release.

Plant superintendant John Castero said the plant workers were able to stop the flow into the bay at about 6 a.m. after diverting flow into other tanks. He said a surge in rainfall between 3 and 3:30 a.m. Wednesday morning, coupled with the plant construction for the enhanced nutrient removal upgrade, “really pushed us over the edge hydraulic-wise over the tanks.”

During the two-hour span, Castero said the plant was discharging half of the overflow into other tanks and the remaining half into the Chesapeake Bay.

“We finally were able to divert enough flow around to completely stop all discharges to the Chesapeake Bay until we could get the tanks that were causing the solids loss to drain back down,” Castero said.

Beginning at about 3 p.m. Tuesday, Castero said the plant began diverting flow in anticipation of the forecasted rainfall, but “the little spurt of heavy rainfall knocked us over about 2 inches before we could control the rest of it.”

Castero said 60,000 gallons “is really not a significant amount of solids,” and the pollution factor from the loss “is probably minimal.”

“We were able to contain it pretty quick,” he said.

During the three-year ENR upgrade at the treatment facility, which began June 10, there are several tanks being demolished and new ones constructed, which Castero said contributed to the overflow and resulting discharge into the bay.

“Hopefully, if the weather holds up over this [project] period, we won’t have large overflows,” he said.

The Calvert County Health Department and the Maryland Department of the Environment have been notified of the discharge, the release states, and other reporting procedures will be completed Wednesday. Both of those offices are closed for the Thanksgiving holiday, but Castero said he has left messages detailing the incident.

Tests currently are being conducted to determine the pollution factor, he said, and tests will continue for the next 48 hours. However, the need for additional testing will be determined and conducted by the health department.